GL.Begin 开始

static function Begin (mode : int) : void

Parameters参数

Description描述

Begin drawing 3D primitives.

开始绘制3d原始物体。

In OpenGL this matches glBegin; on other graphics APIs the same functionality is emulated. Between GL.Begin and GL.End it is valid to call GL.Vertex, GL.Color, GL.TexCoord and other immediate mode drawing functions.

这和OpenGL中的glBegin函数一样。其它的图形API中也有类似的函数。在GL.Begin 和 GL.End之间放置GL操作函数。

You should be careful about culling when drawing primitives yourself. The culling rules may be different depending on which graphics API the game is running. In most cases the safest way is to use Cull Off command in the shader.

在用到裁剪函数时特别注意,这依赖于特定的图形API,不同的API裁剪方式不同。在多数情况下最好是用shader 中Cull Off命令。

参见:GL.End

using UnityEngine;
using System.Collections;

public class example : MonoBehaviour {
    public Material mat;
    void OnPostRender() {
        if (!mat) {
            Debug.LogError("Please Assign a material on the inspector");
            return;
        }
        GL.PushMatrix();
        mat.SetPass(0);
        GL.LoadOrtho();
        GL.Begin(GL.TRIANGLES);
        GL.Color(new Color(1, 1, 1, 1));
        GL.Vertex3(0.5F, 0.25F, 0);
        GL.Vertex3(0.25F, 0.25F, 0);
        GL.Vertex3(0.375F, 0.5F, 0);
        GL.End();
        GL.Begin(GL.QUADS);
        GL.Color(new Color(0.5F, 0.5F, 0.5F, 1));
        GL.Vertex3(0.5F, 0.5F, 0);
        GL.Vertex3(0.5F, 0.75F, 0);
        GL.Vertex3(0.75F, 0.75F, 0);
        GL.Vertex3(0.75F, 0.5F, 0);
        GL.End();
        GL.Begin(GL.LINES);
        GL.Color(new Color(0, 0, 0, 1));
        GL.Vertex3(0, 0, 0);
        GL.Vertex3(0.75F, 0.75F, 0);
        GL.End();
        GL.PopMatrix();
    }
}
// Draws a Triangle, a Quad and a line
// with different colors
//绘制具有不同颜色的一个三角形、一个方形和一条线
var mat : Material;
function OnPostRender() {
    if (!mat) {
        Debug.LogError("Please Assign a material on the inspector");
        return;
    }
    GL.PushMatrix();
    mat.SetPass(0);
    GL.LoadOrtho();
    GL.Begin(GL.TRIANGLES); // Triangle
    GL.Color(Color(1,1,1,1));
    GL.Vertex3(0.50,0.25,0);
    GL.Vertex3(0.25,0.25,0);
    GL.Vertex3(0.375,0.5,0);
    GL.End();
    GL.Begin(GL.QUADS); // Quad
    GL.Color(Color(0.5,0.5,0.5,1));
    GL.Vertex3(0.5,0.5,0);
    GL.Vertex3(0.5,0.75,0);
    GL.Vertex3(0.75,0.75,0);
    GL.Vertex3(0.75,0.5,0);
    GL.End();
    GL.Begin(GL.LINES); // Line
    GL.Color(Color(0,0,0,1));
    GL.Vertex3(0,0,0);
    GL.Vertex3(0.75,0.75,0);
    GL.End();
    GL.PopMatrix();
}
Page last updated: 2012-7-5